Variable-speed mechanism



Sept. 18, 1928.

W. G. HUMPHREYS VARIABLE SPEED MECHANISM 3 Sheets-Sheet 1 Filed May 13,1926 W.G.Humphreys 3 MM 1% Sept. 18, 1928. 1,684,705

W. G. HUMPHREYS VARIABLE SPEED MECHANISM v Q gnwntoz W.G.HumphreyS Sept.18, 1928.

W. G. HUMPHREYS VARIABLE SPEED MEcHANIsM 5 Sheets-Sheet 3 Filed May 1 3,1926 Patentedsept. 18,1928. p i. 1,684,705.-

umrso STATES PATENTFOFFICEa WALTER G. HUMPHREYS, OF OMAHA, NEBRASKA.

VARIABLE-SPEED MECHANISM.

Application filed May 13, 1925. SerialNo. 108,847.

This invention relates to variable speed consisting of a miter gear 12adapted to enmechanism useful for many purposes and gage the miter'gear13 carried bya' driven particularly adapted for use in connection shaft14 which projects outwardly from the with vehicles equipped withexcavating or transmission housing 15 ofthe tractor at trench diggingmechanism, described in Let-. right-angles to said shaft 10. ters Patentof the United States Nos. Other parts include a spur-gear 16 mount-'1.419,381 and 1.419382, dated June 13, 1922, ed on said shaft 10adapted to be placed in i the principal object being to permit theveengagement, selectively, with a gear wheel 17 hicle to be driven whilethe trench or excavahaving amounting on a worm shaft 20, these 10 tionis formed, and to control the speed of the parts .being designatedusually as transmis vehicle while the digging mechanism consionmechanism and common to tractors.

tinues at normal speed. v d Other conventional parts include a gear" Inthe operation of digging trenches the shift lever 18, by means of whichan opera vehicle moves on the ground surface at the tor, at desiredtimes, may cause the spur- 15 front of the trench, and since the groundmay gears 16 and 17 to become engaged. Numeral be rough or undulating,the time required in 19 indicates a clutch pedal, by means of forming atrench will depend on its depth which, an operator may cause the clutch11 to and. density of the ground to be excavated function.

vention provides means which may be con- 14 is. generally found ontractors of the class veniently controlled by an operator, wherebydescribed, and may be used for'various purand will not be uniform. Thepresent in- It will be understood that the drive shaft the vehicle maymove at selected degrees of poses. While none of the parts thus men- Ispeed without disturbing the normal speed tioned are claimed as new, thepresent invenrequired for the excavating mechanism. tion includescertain mechanism used in con- 25 In preparing the accompanying drawingsnection with the driver shaft 14. I

it has not been considered necessary to illus- By the use of the shaft 11 the vehicle may trate the digging mechanism described in the bepropelled whenever desired, its movements Letters Patent referred to,nor necessary to being as slow as may be required, this being illustratethe operating parts of the engine of of great advantage in instanceswhere the 8.0 3 a tractor of conventional type, such as is protrench hasa considerable depth, or the earth vided for a Fordson tractor inconnection to be excavated is more dense or hard than with which thepresent invention is illususual, certainmechanism to be described', be-

trated. ing employedfor this purpose.

In the drawings: When moving the vehicleupon a highway 35 Fig. 1 is aplan view partly in section,showor from one location to another, anoperator ing the variable speed mechanism. may causethe rotary motion ofthe engine I Fig. 2 is a view of the same in longltudinal shaft to becommunicated directly to the section. Y worm shaft 20'bv causingengagement of the Fig. 3 is an enlarged sectional detail view gears 16and 17 the clutch members 48 and 4A showing the worm shaft and itsconnections. being disconnected at this time.

4 is a broken away rear end. View of To cause the slow or creepingmovement parts shown in Fig. 1. I of the vehicle mentioned, an operatorvmay In the present instance the engine is pro place the gear shift lever18 in neutral posivided with a shaft 10 adapted to be rotated tion,whereby the geariwheels 16 and 17 will 45 by the engine crank-shaft (notshown), it benot be in engagement, the drive shaft 14 howing understoodthat a clutch 11 is provided ever being rotated by the rotation of shaft10, and may be used for communicating rotation said shaft 10'beingrotated on account of the to said shaft 10 from thecngine shaft. Theseengine shaft when the latter is coupled with parts are shown in dottedlines for the reason the shaft 10 by means of the clutch 1'1.

that they are in general use and are found on It will therefore benoted'that power de all Fordson tractors, other conventional parts rivedfrom the rotation of the engine shaft Y may be applied directly to theworm shaft 20 or may be applied as described, for rotating shaft 23being provided-with wheels and the shaft 14. y

In order that the objects may be attained as first mentioned, certainmechanism is provided and now to be described, consisting in part, of anidler pulley 21 mounted on the drive shaft 14 at its outer end andadapted to be rotated by said shaft by means of a clutch 22 which issplined upon and is movableor slidable on this shaft.

Numeral 23 indicates an operating shaft which is disposed transverselyof the vehicle and has bearings in a suitable frame 24 which extendsabove the body of the vehicle, said 26 and having an alternating gearsleeve 27 splined thereon. V i

Numeral 28 indicates and auxiliaryshaft having hearings in the frame 24and provided with wheels 29 and 30. At 31 isindicated a beltengaging'the wheels 21 and 25, and at 32 is indicated a beltada-pted toengage the wheels 26 and 29, the parts mentioned being adapted to movethe flexible endless excavator belt 33 which is mounted on the wheel 30of the auxiliary shaft. While the elements 31 and 32 havebeen designatedas belts for engaging the wheels mentioned, sprocket chains or othergearings could be used, but since the ground to be excavated is notalways free from rocks or 7 other obstructions,.belts are preferred, toprevent injury to the mechanism, and the partsthus mentioned may haveany suitable pro-- portions corresponding to the degree of-rota- .tionof the shaft 14 for excavating, or for other purposes including theformation of trenches.

In order that the vehicle may move slowly and may be moved atselecteddegrees of speed, a stub shaft 34 in suitable bearings isprovidedwith a suitable number of sprocket wheels differing in diameter,indicated at 35,

36 and 37 and having amiter gear 38 for engaging the alternating gear 27of the operating shaft.

Numerals 39, .40 and 41 indicate sprocket.

wheels difleringin' diameter carried by the extension 20 of theworm'shaft 20, a sprocket chain 42 being in engagement with the wheels37 and41. As described a rotation of the shaft 23 will cause a rotationof the stub shaft 34 for rotating the extension 20' of the worm shaft.Numeral 43 indicates a clutch-member which is splined on the extension20 normally pressed into engagement with a clutch-memher 44 carried bythe worm shaft but under control of a hand lever 45, and, as is obviouswhen the clutch members are in engagement the worm shaft will berotated'for actuating the worm wheel .46, thelatter being mounted on thepropeller shaft 47, having suitable bearings, and provided at its endswith sprocket wheels 48. The vehicle Wheels 49 at the respective sidesof the vehicle body are provided Wth sprocket wheels 50, and sprocketchains 51 communicate the rotatable movements of the wheels 48 to thewheels 50 for-rotating the vehicle wheels 49.

It will be understood that the sprocket chain 42 may be removed from thewheels 37 and 41, and that sprocket chains of greater length may be usedand that the wheels 36 and 40 may be engagedby a chain, or the wheels 35and 39 may be engaged by a chain, and by the means described the vehiclemay have the desired slow or creeping movements mentioned. i

It will be noted that the means employed for controlling the speed ofthe vehicle-as outlined willnot change the speed of the operating partsof the excavating mechamsm. The shafts 14, 23 and 28 may rotate at anormal high degree of speed while the shaft 47 and vehicle wheels 49rotate at reduced degrees of speed.

While I haveshown in Fig, 2 of the drawings that vehicle wheels 49 areused in pairs and are engaged by endless belts 52 which engage theground, this feature is not important, and while the construction shownis preferred, I may use other kinds of vehicle wheels if desired. I

One of the advantages to be deriv'ed'by use of the alternating gearsleeve 27 is that it may be moved on the shaft 23 to cause the mitergear 38' of the stub shaft 34 to engage one of the miter gears X of thegear sleeve to reverse the movement ofthe vehicle, since in someinstances a rearward movement is desirable.

As already stated, an operator, by causing engagement of the gears 16and 17 may cause actuation of the worm shaft direct from the engineshaft, and if the worm shaft20 is not coupled with the worm-shaftextension 20' a suitable degree of speed.

. I claim as my invention 1 1. In driving mechanism for a vehicle, aframe .a drive shaft mounted transversely in the frame, a transversepropeller shaft, a transverse operating shaft spaced from the propellershaft and exposed for connection with devices to be power driven, alongitudinally disposed shaft connected to the propeller shaft, a stubshaft disposed in parallel relation to the longitudinal shaft,registering gear sets on the stub and longitudinal shafts, a chainselectively connecting gears of said sets to drive through said shaftsat the desired ratio, gearing connecting the stub and operating shafts,and a connection between the operating and drive shafts.

2. In driving mechanism for a vehicle, the combination with the usualpropeller shaft, power shaft and disengageable gearing there: between, adrive shaft connected to the power shaft in advance of said gearing, anoperating shaft connected through a clutch to said drive shaft, a stubshaft reversibly connected to the operating shaft, another shaftdisposed in parallel relation with the stub shaft, registering variablespeed gears on'the stub and said last named shafts, a shiftableconnection between said gears for connecting the respective shafts invarious ratios, and a clutch connection between said last named shaftand the propeller shaft.

In testimony whereof, I have affixed my signature. I 1

WALTER G. HUMPHREYS.

